Pencil lead sharpener



Feb. 27, 1951 H. M. M CLURE PENCIL LEAD SHARPENER Filed Sept. 3, 1948 IN VEN TOR. Huw/ M. Ma CA was H/; A Tram/5y Patented F eb. 27, 1951 UNITED STATES PATENT FFlCE PEN CE LEAD SHARPENER Hugh M. McClure, Chicago, Ill.

Application September 3, 1948, Serial No. 47,583

11 Claims. 1

This invention relates to pencil lead sharpeners and particularly to sharpeners of the type disclosed in the co-pendi-ng application of Hugh M. McClure, Serial Number 768,129, filed August 12, 1947, and entitled Pencil sharpeners.

In said co-pending application, there is disclosed a lead sharpener which consists essentially of a base or holder and two abrasive strips. The base is of a trough like construction defined by a curved or rounded apex and side walls which converge from a wider end to a closed end with the angle of convergence constantly varying and the walls themselves being inclined with respect to one another and opening upwardly with a varying angle. The base also carries an upwardly turned extension that is so disposed in relation to the walls as to cooperate therewith, in holding the abrasive strips in effective position between the walls.

The present invention has as its foremost objective, the provision of certain improvements in a lead sharpener of the type above indicated.

A still further object of the invention is to provide a holder for a pair of thin springy abrasive strips, so constructed that application of the stri s thereto positions and shapes them in a fashion to produce the characteristic features of the device by retaining such strips in a manner to permit their yielding to undue pressure from a pencil lead drawn therebetween, thus providing resilient lead sharpening surfaces between which such lead may be sharpened as desired without breaking.

Still another object of the. invention is to provide a holder wherein abrasive strips employed in connection therewith, are readily insertable and replaceable, and wherein the springy properties of the abrasive strips are utilized for retainin the same inoperative position.

These objectives are achieved by providing a holder having main wall section of the same general type as those described in said co-pending application but which do not extend along the entire length of the holder. They stop short ofthe wider open end of the holder. Spaced from these main wall sections there are a pair of ears and at the open end there are a pair of lugs. The abrasive strips are placed so that their end portions are fitted within the lugs, the next adjacent portions arranged outwardly of the ears, and the remainder within the main wall sections. Thus, the abrasive strips are woven in between the lugs, ears and main wall sections to hold them in position and impart thereto yielding and resilient characteristics 2 which peculiarly adapt them to the lead sharpening operation.

Still another objective is to provide a holder of the type indicated with a base plate that is substantially in alinement with the base line of the holder and which is adapted to bear against a supporting surface. This plate is in contrast to the upturning extension in the holder of the co-pending application.

Other and further objects of the invention will appear from the specification and claims and from the accompanying drawings, in which:

Figure 1 is a perspective view illustratin one manner of using the invention.

Figure 2 is a side elevational View of the invention.

Figure 3 is a top plan view of this invention.

Figure 4 is an enlarged end elevation, as seen from line 4-4 of Figure 2.

Figure 5 is an enlarged cross sectional view taken in the proximity of line 5-5 of Figure 2,

Figure 6 is an enlarged cros sectional view taken in the proximity of line 6-6 of Figure 2,

Figure '1 is an enlarged cross sectional view taken in the proximity of line 'l-'l, of Figure 2, and

Figure 8 is a perspective detailed view of an abrasive strip employed in connection with the invention.

As shown in Figures 1 through '7 of the drawing, the illustrated embodiment of the invention comprises an elongated holder A, preferably made of stainless steel, although it may be constructed of any other suitable material, such as plastic. The holder forms an elongated trough and in cross section is substantially V-shaped, having a rounded apex portion I and side walls 2 and 3. From one end of said holder, indicated by numeral 4, the ide walls 2 and 3 diverge laterally and longitudinally at uniformly constantly changin cross sectional angles, starting with their slightly angular character shown in Figure 4, and graduall increasing, as shown in Figures 5, 6 and '7 to a point toward the opposite end 5 of the holder A.

Toward the end of the trough part of the holder A, opposite from the end i, the side walls 2 and 3 flare apart at their upper edges, terminating in diverging flares l and 8, as will be understood from the dotted lines in Figure 3. Said flares extend almost to the ears 9 and I0, which are formed upwardly from the apex portion ll, along the trend of said diverging flares, but inwardly therefrom, an appropriate distance for the ear 9 to spring the abrasive strip H against the side wall 2, and likewise the abrasive sheet 12 against the side wall 3 by ear l0. Beyond the other end of the ears 9 and 10, from said side walls, wall sections l3 and M are also formed upwardly from the apex portion I, said sections being in the trend of the flares l and 8, as spaced continuations thereof, and the ears 9 and 10 also serve to hold the abrasive strips sprung against said sections.

The abrasive strips II and 12 are preferably in the category of sand or emery coated sheet material and are efliciently provided by coating strips or thin hard wood with graded sand or emery pulverals, from which it will be understood that said sheets are very readily and conveniently threaded in place along the above mentioned side walls, ears and sections, as described.

When the abrasive strips H and I2 are sprung outwardly by the ears 9 and 10, respectively, against the adjacent ends of the walls 2 and 3, said strips are thus sprung away from said walls for considerable distance in the region B of Figure 1 and to some extent as far as the holder end 4, as indicated in Figure 5, by which feature it will be understood that in passing a pencil lead along between the spring away regions of said strips, said strips yield from any undue pressure from such lead and thus serve as resilient abrasive surfaces which insure against breaking the pencil lead in the sharpening operation.

Referring to Figures 2 and 3, the apex formation I extends longitudinally beyond the sections l3 and M in the form of a somewhat thin lug I5, which serves as a projecting base plate for the trough portion of the holder A, said lug being geometrically at right angles to a plane, bisecting said trough longitudinally. The apex line of the formation I is offset slightly downward from said lug, giving ample clearance for the end of the pencil point as it is passed along between the abrasive strips l i and [2, said lug serving to some extent as a floor to determine a safe starting position of the pencil lead in its path between said strips, it being understood that there is no obstruction in the device from one end to the other, which has to be reckoned with in passing a pencil point through in the sharpening operation.

A hole I8 is provided through the lug l of suitable size to be engaged by an ordinary thumb tack H, or the like, by which the device may be either temporarily or permanently secured to a draftsmans fragmentarily shown drawing board iii, in Figure 2, or to a table or desk (not shown), when it is advantageous to use the device in fixed position, it being obvious that when a pencil is being manipulated by one hand under such circumstances in the sharpening operation, the other hand is free as distinguished from the manner of using the device as illustrated in Figure 1. It will be also understood that the device may be suspended by a string 22, indicated in Figure 1, or the like, tied through said hole in accordance with the custom of many draitsmen in thus suspending their lead sharpening means in convenient reach.

It will be understood that the device may be secured either to a vertical or horizontal surface or to a surface at any angle, as desired.

By referring to Figure 2, it will be observed that the lug I5 is curved downwardly to bring the end thereof in line with the lower or base line of the apex portion I, by which feature, said end is held directly against the drawing board [8. by the thumb tack I1, and said apex portion is also thus held in contact against said drawing board throughout its length.

It will be apparent that when the strips l I and 12 are in position in the holder A the abrasive surfaces ill of said strips provide a wide flaring entrance between the regions 20 and ii, which extend divergently, but to a greater extent at the upper edges of said strips, thus giving said regions a twisted curve character. The lead of a drafting pencil, for example, may be entered between the thus spaced ends of the abrasive surfaces l9 and be drawn therebetween to beyond their other ends. If it is desired to needle point the lead, the pencil is twirled on its axis by the fingers, while the lead is being thus drawn between said surfaces, and if a chisel point is preferred the twirling action is omitted, the tapered character of the pencil point being in either instance deter-- mined by the V arrangement of the abrasive surfaces, and a point ideally suited to drafting is given the lead. There is no tendency of the thus shaped point to break because of the resilient disposition of the abrasive strips as held by the holder A.

The strips H and I2 should extend longitudinally beyond the holder end t and beyond the Wall sections [3 and I4. Said strips should be wider than the height of the walls 2 and 3, but narrow enough to clear the wood or metal part of the pencil, of which the lead is being sharpened.

It will be obvious that when a long tapered point is required on the pencil lead, the pencil is applied at a rather sharp angle to th device, as illustrated in Figure 1, and that when a shorter tapered point is required, the pencil is applied at a more vertical position, as indicated by the dotted lines 23 of Figure 1.

It has been found that the invention has other efiicient uses aside from sharpening pencil leads, for example, in sharpening orange sticks by sculptures or a stylus for mimeograph work. It may also be successfully used in sharpening, and especially in resharpening, machinists steel scratch awls or the like.

Assuming a round pencil lead, which has not been previously sharpened, is drawn through the device in the sharpening operation, the extreme end of the lead first engages the abrasive surfaces I9 upon reaching a point where the distance between said surfaces is the same as the lead diameter, and as the lead thus proceeds it is sharpened from its end up to the end of the taper sharpened portion, the length of which gradually increases from the extreme end of the lead.

While I have illustrated and described the preferred form of construction for carrying my invention into effect, this is capable of variation and modification without departing from the spirit of the invention. 1, therefore, do not wish to be limited to the precise details of construction set forth, but desire to avail myself of such variations and modifications as come within the scope of the appended claims.

The invention claimed is:

1. In a trough type pencil lead sharpener open to a pencil point moved therethrough, throughout its length, and having a bottom and diverging walls flared apart toward one end of the sharpener, a pair of wall sections spaced from said walls in the trend of the flares thereof, abrasive strips lining each of said walls and respective sections and extending thereabove to provide resilient strip portions, and ears serving to retain said abrasive strips against said walls and sections, said abrasive strips having a compound 5. curvature made up of a diverging relation between said strips from their bottom edges upwardly and a flare from one end to the other.

2. In a trough type point Sharpener open to a point moved therethrough, throughout its length, and having a bottom and diverging walls flared apart at one end of the holder, a pair of wall sections spaced from said walls in the trend of the flares thereof, abrasive strips lining each of said walls and respective sections and extending thereabove to provide resilient strip portions, ears serving to retain said abrasive strips against said walls and sections, said abrasive strips hav ing an upward divergence and an end to end flare providing a compound curvature therein, and a base plate extending longitudinally from said bottom, said plate serving to determine the resting position of said holder.

3. In a pencil lead sharpener utilizing abrasive strips, a trough shaped holder, having a bottom and diverging walls flared apart toward one end of the sharpener, a pair of wall sections spaced from said walls in the trend of the flares thereof, abrasive strips lining each of said walls and respective sections and extendin thereabove to provide resilient strip portions, and ears serving to retain said abrasive strips against said walls and sections, said abrasive strips having a compound curvature providing a closely spaced, substantially parallel relation at one end and a widely spaced flare at the other end.

4. In a point sharpener utilizing abrasive strips, a trough shaped holder, having a bottom and diverging walls flared apart at one end of the holder, a pair of wall sections spaced from said walls in the trend of the curves thereof, abrasive strips lining each of said walls and respective sections and extending thereabov to provid resilient strip portions, ears serving to retain said abrasive strips against said walls and sections, said abrasive strips having a compound curvature providing a closely spaced, substantially parallel relation at one end and a widely spaced flare at the other end, and a base plate extending longitudinally from said plate serving to determine the resting position of said holder.

5. In a pencil lead sharpener using abrasive strips, a trough shaped holder for such strips, said holder having an apex base line and having a base plate in near alignment with said base line, restricting such sharpener to working position on a table or wall to which it is secured.

6. In a pencil lead sharpener using abrasive strips, a trough shaped holder for such strips, said holder having a base line and having a base plate in near alignment with said base line restricting such sharpener to working position on a flat surface, said base plate having a hole for securing said sharpener to either a horizontal, slanting, or vertical surface as desired.

7. In a lead sharpener using abrasive strips, a trough shaped holder for such strips, said holder having a base line and havin a base plate in near alignment with said base line restricting such sharpener to work in position on a table or the like, said base plate having a surface for gaging the starting position of a point in the sharpening operation and said base having a point in line with said base line.

8. In a pencil lead sharpener using abrasive strips, a trough shaped holder having a pair of diverging walls flared apart toward one end of the holder, a pair of wall sections spaced from said walls in the trend of the flares thereof, and ears serving to hold abrasive strips against said walls and respective sections when inserted along the inner sides thereof.

9. In a point sharpener using abrasive strips, a trough shaped holder havin a pair of diverging walls flared apart at one end of the holder, a base plate extending from said holder end, a pair of wall sections formed on said plate spaced from said walls in the trend of the flares thereof, and ears also formed on said plate, serving to hold abrasive strips against said walls and respective sections when inserted along the inner sides thereof.

10. In a pencil point sharpener using at least one abrasive strip, a holder having at least one flared wall, at least one wall section spaced from said wall in the trend of the flare thereof, and at least one ear serving to hold such a strip against such wall and section in working position.

11. In a pencil point sharpener using an abrasive strip, a holder having a flared wall, a Wall section spaced from said wall in the trend of the flare thereof, an ear serving to hold such a strip against said wall, and section; and another wall, ear and section arranged complementarily to the preceding wall, ear, and section in working relation therewith.

HUGH M. MCCLURE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 66,689 Durgin July 16, 1867 185,030 Hennaman Dec. 5, 1876 300,375 Knagge June 17, 1884 500,504 Moore June 27, 1893 573,364 Simonds Dec. 15, 1896 705,322 Cortes July 22, 1902 1,522,958 Land Jan. 13, 1925 2,238,340 Poe Apr. 15, 1941 

